TiO2 nanoparticles incorporated with CuInS2 clusters: preparation and photocatalytic activity for degradation of 4-nitrophenol

TiO2 nanoparticles incorporated with CuInS2 clusters were prepared in a solvothermal process and characterized with X-ray diffraction (XRD), transmission electron microscopy (TEM), and energy-dispersion X-ray analysis (EDX). Compared with pure TiO2 nanoparticles, the TiO2 nanoparticles incorporated with CuInS2 clusters display higher photocatalytic activity with 99.9% of degradation ratio of 4-nitrophenol after 2 h irradiation. In order to investigate the effect of the CuInS2 clusters on the photocatalytic activity of TiO2 nanoparticles, diffuse reflectance UV–Vis spectra (DRS), photoluminescence (PL) spectra, and photocurrent action spectra were measured. The results indicate that the enhanced photocatalytic activity is probably due to the interface between TiO2 and CuInS2 as a trap of the photogenerated electrons to decrease the recombination of electrons and holes.